{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T11:13:57Z","timestamp":1790248437908,"version":"4.1.0"},"reference-count":22,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,6,8]],"date-time":"2026-06-08T00:00:00Z","timestamp":1780876800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>This study aims to explore the gestational dynamics of maternal thyroid hormones and their associations with neonatal birth outcomes (birth weight, length, and parity), including 2,884 pregnant women (287 in early, 807 in mid, and 1,487 in late pregnancy).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Using univariate ANOVA to assess trimester-specific thyroid hormone differences, linear mixed-effects models to examine associations with neonatal outcomes, restricted cubic spline (RCS) plots to evaluate dose-response relationships, and Bayesian kernel machine regression (BKMR) to analyze combined effects of thyroid hormone mixtures.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>We found that maternal Thyroid Stimulating Hormone (TSH), Total Triiodothyronine (TT3), Free Triiodothyronine (FT3), and Free Thyroxine (FT4) levels changed significantly with gestation (TSH increasing gradually, TT3 peaking in mid-pregnancy, and FT3\/FT4 declining continuously), Weak correlations were observed between maternal thyroid hormones and neonatal outcomes, with mixed linear regression revealing trimester- and sex-specific associations of TT4, TT3, FT3, and FT4 with birth weight, length, and parity. RCS analysis further showed dose-response relationships with pregnancy-stage and sex-specific patterns, while BKMR indicated weak positive correlations of thyroid hormone mixtures with neonatal outcomes in early\/mid-pregnancy and significant positive correlations in late pregnancy. The relative contribution of each thyroid hormone to neonatal outcomes was also quantified.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Collectively, our findings highlight trimester-specific thyroid hormone dynamics, complex dose-response relationships with neonatal outcomes, and stage\/sex-dependent associations, underscoring the need for gestational thyroid function monitoring to inform maternal\u2013infant health strategies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fendo.2026.1850925","type":"journal-article","created":{"date-parts":[[2026,6,8]],"date-time":"2026-06-08T04:23:54Z","timestamp":1780892634000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Associations between maternal thyroid hormones and neonatal outcomes during pregnancy"],"prefix":"10.3389","volume":"17","author":[{"given":"Lin","family":"Tao","sequence":"first","affiliation":[{"name":"School of Public Health, Zunyi Medical University","place":["Zunyi, Guizhou, China"]},{"name":"Centre for Disease Control and Prevention","place":["Guiyang, Guizhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Zhang","sequence":"additional","affiliation":[{"name":"The People\u2019s Hospital of Qian Nan Prefecture","place":["Qian Nan, Guizhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuan","family":"Zhongzhou","sequence":"additional","affiliation":[{"name":"School of Public Health, Zunyi Medical University","place":["Zunyi, Guizhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shen","family":"Xubo","sequence":"additional","affiliation":[{"name":"School of Public Health, Zunyi Medical University","place":["Zunyi, Guizhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,6,8]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/S2213-8587(20)30061-9","article-title":"Association of maternal thyroid function with birthweight: a systematic review and individual-participant data meta-analysis","volume":"8","author":"Derakhshan","year":"2020","journal-title":"Lancet Diabetes Endocrinol"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2016.0457","article-title":"2017 guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and the postpartum","volume":"27","author":"Alexander","year":"2017","journal-title":"Thyroid"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.3389\/fendo.2023.1080969","article-title":"Thyroid hormones and carnitine in the second trimester negatively affect neonate birth weight: a prospective cohort study","volume":"14","author":"Yang","year":"2023","journal-title":"Front Endocrinol (Lausanne)"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1038\/nrendo.2017.93","article-title":"Thyroid disease in pregnancy: new insights in diagnosis and clinical management","volume":"13","author":"Korevaar","year":"2017","journal-title":"Nat Rev Endocrinol"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.3389\/fendo.2020.00610","article-title":"Effect of gestational weight gain on associations between maternal thyroid hormones and birth outcomes","volume":"11","author":"Zhou","year":"2020","journal-title":"Front Endocrinol (Lausanne)"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2016.0459","article-title":"Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and the postpartum","volume":"27","author":"Stagnaro-Green","year":"2017","journal-title":"Thyroid"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa2116452","article-title":"Thyroid hormone requirements during pregnancy","volume":"386","author":"Mladenovic","year":"2022","journal-title":"N Engl J Med"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1210\/clinem\/dgad089","article-title":"Maternal subclinical hypothyroidism and offspring growth: a prospective cohort study","volume":"108","author":"Zeng","year":"2023","journal-title":"J Clin Endocrinol Metab"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1530\/EC-21-0599","article-title":"Association of maternal thyroid dysfunction and autoimmunity with adverse birth outcomes","volume":"11","author":"He","year":"2022","journal-title":"Endocr Connect"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1210\/endocr\/bqac082","article-title":"Maternal thyroid function and birth weight in twins","volume":"163","author":"Liu","year":"2022","journal-title":"Endocrinology"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.3389\/fendo.2020.601956","article-title":"Does maternal normal range thyroid function play a role in offspring birth weight? 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